A primary function of personal care absorbent articles is to absorb and retain body exudates such as urine, fecal material, blood, and menses with additional desired attributes including low leakage of the exudates from the absorbent article and a dry feel to the wearer of the absorbent article. To accomplish these tasks, personal care absorbent articles generally have an absorbent core and a cover enclosing the absorbent core. The cover is usually fluid pervious on the body facing side of the absorbent core and fluid impervious on the garment facing side of the absorbent core. Absorbent articles commonly fail, however, to prevent leakage of body exudates. Some body exudates, such as solid and semi-solid fecal material and menses, have difficulty penetrating the body facing material of the absorbent article as easily as low viscosity exudates, such as urine, and tend to spread across the surface of the body facing material. Such spread of body exudates can result in leakage of the body exudates from the absorbent article.
Semi-solid fecal material, such as low viscosity fecal material which can be prevalent with younger children, and menses can be especially difficult to contain in an absorbent article. These exudates can move around on the body facing material of an absorbent article under the influence of gravity, motion, and pressure by the wearer of the absorbent article. The migration of the exudates is often towards the perimeter of the absorbent article, increasing the likelihood of leakage and smears against the skin of the wearer which can make clean-up of the skin difficult. Even if the migration of exudates is minimized on the body facing material, another challenge in containing semi-solid fecal material, menses, as well as other body exudates, is efficiently distributing such exudates through the absorbent structure of the absorbent article.
Attempts have been made in the past to provide body facing material to an absorbent article that can solve the problems described above. One such approach has been the use of various types of embossing to create three-dimensionality in the body facing surface of the absorbent article. This approach, however, requires high basis weight material to create a structure with significant topography. Furthermore, it is inherent in the embossing process that starting thickness of the material is lost due to the fact that embossing is, by its nature, a crushing and bonding process. Additionally, to “set” the embossments in a nonwoven fabric, the densified section is typically fused to create weld points that are typically impervious to the passage of body exudates. Hence, a part of the area for body exudates to transit through the material is lost. Also, “setting” the fabric can cause the material to stiffen and become harsh to the touch.
Another approach has been to form fibrous webs on three-dimensional forming surfaces. The resulting structures typically have little resilience at low basis weights (assuming soft fibers with desirable aesthetic attributes are used) and the topography is significantly degraded when wound on a roll and put through subsequent converting processes. This is partly addressed in the three-dimensional forming process by allowing the three-dimensional shape to fill with fiber. This, however, typically comes at a higher cost due to the usage of more material. This also results in a loss of softness and the resultant material becomes aesthetically unappealing for certain applications.
Another approach has been to aperture a fibrous web. Depending on the process, this can generate a flat two-dimensional web or a web with some three-dimensionality where the displaced fiber is pushed out of the plane of the original web. Typically, the extent of the three-dimensionality is limited and, under sufficient load, the displaced fiber may be pushed back toward its original position resulting in at least partial closure of the aperture. Aperturing processes that attempt to “set” the displaced fiber outside the plane of the original web are also prone to degrading the softness of the starting web. Another problem with apertured materials is that when they are incorporated into end products such as with the use of adhesives, due to their open structure, the adhesives will often readily penetrate through the apertures in the material from its underside to its top, exposed surface, thereby creating unwanted issues such as adhesive build-up in the converting process or creating unintended bonds between layers within the finished product.
Attempts have also been made to assist the distribution of body exudates throughout an absorbent structure through the use of acquisition layers and fluid transfer layers that are placed between the absorbent body and body facing materials. While such acquisition and fluid transfer layers may distribute some exudates on a two dimensional level in longitudinal and latitudinal directions on the body facing surface of the absorbent body, these acquisition and fluid transfer layers provide little benefit of distribution to the side or garment facing surfaces of the absorbent body.
There remains a need for an absorbent article that can adequately reduce the incidence of leakage of body exudates from the absorbent article. There remains a need for an absorbent article which can provide improved handling of body exudates. There remains a need for an absorbent article that can minimize the amount of body exudates in contact with the wearer's skin. There remains a need for an absorbent article that can more effectively distribute body exudates throughout the absorbent structure. There remains a need for an absorbent article that can provide physical and emotional comfort to the wearer of the absorbent article.